When One Gene Influences Many Phenotypic Expressions It is Said

Question

When one gene influences many phenotypic expressions it is said to be:
A) Incompletely penetrant
B) Variably penetrant
C) Pleiotropic
D) Epistatic
E) Polygenice

Accepted Answer

When one gene influences many phenotypic expressions, it is said to be pleiotropic. Pleiotropy occurs when a mutation in a single gene affects multiple phenotypic traits. For example, sickle cell anemia is caused by a mutation in the HBB gene, which results in abnormal hemoglobin. This mutation can cause not only anemia but also other health-related problems such as fatigue, jaundice, and pain episodes.